RE: Re: [PATCH v4 1/4] dt-bindings: net: phy: Add support for NXP TJA11xx

[Christian Herber <christian.herber@nxp.com>]

>On Sun, Mar 22, 2020 at 3:09 PM Florian Fainelli <f.fainelli@gmail.com> wrote:
>>
>> On 3/20/2020 4:05 PM, Rob Herring wrote:
>> >>>> Because the primary PHY0 can be autodetected by the bus scan.
>> >>>> But I have nothing against your suggestions. Please, some one should say the
>> >>>> last word here, how exactly it should be implemented?
>> >>
>> >> It's not for me to decide, I was hoping the Device Tree maintainers
>> >> could chime in, your current approach would certainly work although it
>> >> feels visually awkward.
>> >
>> > Something like this is what I'd do:
>> >
>> > ethernet-phy@4 {
>> >   compatible = "nxp,tja1102";
>> >   reg = <4 5>;
>> > };
>>
>> But the parent (MDIO bus controller) has #address-cells = 1 and
>> #size-cells = 0, so how can this be made to work without creating two
>> nodes or a first node encapsulating another one?
>
>That is the size of the address, not how many addresses there are. If
>the device has 2 addresses, then 2 address entries seems entirely
>appropriate.
>
>Rob

Yes, it is one device with two address. This is if you call the entire IC a device. If you look at it from a PHY perspective, it is two devices with 1 address.
If you just look at it as a single device, it gets difficult to add PHY specific properties in the future, e.g. master/slave selection.
In my opinion its important to have some kind of container for the entire IC, but likewise for the individual PHYs.

Christian